Pug mill



March 13, 1928.

M. MADSEN PUG MILL Filed April 20, 1927 2 Sheets-Sheet 1 Patented Mar. 13, 1928.

UNITED STATES PATENTOFFECE.

MARTIN MADSEN, or monrrnnnx PARK, CALIFORNIA.

I PUG MILL.

Application filed April 20,

considerable expense. It is the object of my invention to improve the pug mill by mak-' ing the box thereof with a sectional bottom and with the sections reversible so that when the edges of the side portions become too much worn to function properly that such sections can be quickly and easilychanged to position the con'iparatively unworn edges for the fully worn edges and when the second edge wears out the section can be quickly and easily replaced by a new one. Another object is to provide a removable central portion which when worn out can be quickly and easily replaced by a new one. Another object is to provide removable and adjustable discharge gates. Other objects will appear later.

In the drawings forming a part of this application: j

Fig. 1 is a side elevation partly in section of my improved pug mill;

Fig. 2 is an end view, partly in section;

Fig. 3 is a top plan view with all the paddles omitted except 3;

Figs. 4 to 7 are enlarged views of parts of the mill.

Referring to the drawings the end mem bers of the mixing box are horizontally divided and the top portions are numbered 8 and 9 and the bottom portions 10 and 11. In these end members are mounted the paddle shailts 12 and 13 which carry gears 14 and 15 that mesh with each other. The paddles are mounted on shafts 12 and 13 and except two are shown diagrammatically by dotted lines 18 in Fig. 3 and in enlarged de, tail in Fig. 7. The paddles comprise blades 19 having hubs 20 and collars21 which are secured to the hubs by bolts 22. The hubs and collars have recesses 23 therein provided with toothed shaped perimeters as shown in Fig. 7 so as to position the paddles spirally or otherwise on the shafts as desired." The shafts are square in cross-section and fit into the toothed shaped perimeter. Shafts 12 and 13 are mounted in adjustable bearing takes time to install a new box and involves 'tion of these sections.

1927. Serial No. 185,222.

blocks 24 which are mountedon horizontal ledges 25 projecting horizontally andoutwardly from the outer surfaces of the end member-s. These bearing blocks are adjustably positioned on the ledges by suitable boltsso as to adjust the shafts toward and from each other. The end members have projecting from their inner surfaces curved ledges 26 against which ledges the side sec-' tions of the bottom pieces of the box'abut. These sidebottom pieces comprise the reversible .curvedinembers 2'Twhose ends are rabbeted to rest againstthe ledges of the end- ,to unite them to the lugs 31 on the end members. These bottom side pieces areof the I same configuration so as to lit on eitherside" and to have either edge uppermost, thereby permitting the turning of the section to substitute a less worn edge in the position formerly occupied by a greater worn edge. It will be understood that there is more weal on the bottom portion than on the top por- This reversibility prolongs the life of usefulness of these portions of the bottom of the box. A central bottom section 32 rabbeted at the ends to fit upon the ledges of the end members and along the side edges to receive the edges of the side pieces is secured to the end pieces by suitable lugs and bolts. In the central portion of section 32 is adischarge opening 33 which when the mill is being operated is covered by a gate 34.

Gate 34.- is slidably mounted upon gate bars 35, one on each side of the gate. Bars 35 are carried by brackets 36 secured to and at the cornersofsection 32. These brackets carry adjusting screws 37 by means of which bars 35 can be adjusted to take up any wear on the bars or on gate 34. Attached to one endol gate 3a is the gate operating bar 38 which is operated by any suitable power, de-

vice. In Fig. 1 I have shown a pneumatic device 39 by means of whichthe gate is opened or closed.

Section 32 also has brackets 50 that project under the bottom edge of members 27 as best shown in Fig. 2. Brackets 50'carry adjusting screws 51 so that the abutting edges of 27 and 32 maybe in the same plane.

The upper portion of the mixing box is composed of the upper side members 40 and -t1 and end members 8 and 9. Members 40 and 41 have lips 42 that fit over the upper projecting forked lugs 43 in which are received the ends of rods 44 whose ends are threaded and carry nuts 45. When the parts are positioned and the nuts tightened the upper portions of the box are securely held upon the lower portions. Power is applied to shafts 12 or 13 to operate the paddles.

Having described my invention, I claim 1. A pug mill comprising a mixing chamher having a sectional bottom composed of a central section. having a discharge port therein, and two interchangeable reversible side members adapted to be reversed edge for edge and end for end; two addle shafts, adjustably mounted in the en members of said chamber; paddles on said shafts; a longitudinally sliding gate adapted to control said discharge port; means to adjust the position of said gate; and means to adjust the upper surfaces of the lower edges of the side bottom members with reference to the upper surfaceof the adjacent edges of said central memben a 2. A pug mill provided with mixing chamberhaving a bottom composed of side members and a central member, said central memher having a discharge opening therein; said s de members being of the same configuration and being adapted to be reversed edge *for edge and end'for end; means to adjust the lower edges of said side members with reference to the adjacent edges of said central member; a gate slidably mounted to control said discharge opening; and means to adjust said gate.

Ina pug mill, a mixing chamber having a sectional bottom composed of a central section with reversely curved surfaces and a discharge opening therein; curved side bottom members, said last members being reversible side for, side and end for end and interchangeable; means to adjust vthe upper surface of the lower edges of said last members to the plane of the upper adjacent surfaces of said central section; a gate slidingly mounted to control said discharge opening; and means to adjust the position of said gate.

In witness that I claim the foregoing I have hereunto subscribed my name this 8th day of April 1927.

MARTIN MADSEN. 

